Dieting: a big fat lie

I have two friends (actually I have more than two, maybe after this I will have two fewer), one of whom is well endowed. She's big. The other one is fairly small, actually flat-chested. The large one wishes she was small, and the small one would love to have something in her bra, apart from padding. The other day, I thought of a new way to help them both - and save the NHS millions. It's a system called "Co-Operations". You basically find two people in need, and you pair them up, and give each what they want. So one loses a bit, and the other gains. All happy. OK, I haven't perfected the techniques, but the idea sounds quite good.

If only life were so simple. One woman who came to see me had a big dance to go to at at the weekend. Her son had bought her a dress. Just one little problem: he had bought it two sizes too small. She was sure that I must have something in my doctor's bag that would melt the pounds, and reduce her from a size 16, to a size 12 in three days.

We all want instant results. That's why every time a new diet comes out, we all follow it like sheep. Remember the grapefruit diet, the baked bean diet (not a very sociable one) or the one where you can't mix anything together? One of my patients was desperate to lose weight, and went to a "diet clinic". She had previously been treated for depression. The clinic did not take a proper history, and didn't find this out. She wanted the tablets. She got them, but at a greater cost than money. She ended up on a psychiatric ward, because she became psychotic. She is fine now, but it was a lesson not to be repeated.

The only way to lose weight successfully - as everybody really knows - is to take in fewer calories (the best way to do this is to eat a low- fat, high-carbohydrate diet), and to burn more up. However, the classic calorie-controlled diet can be little more than a short-term solution. One depressing fact is that 50 per cent of all people who go on a calorie- controlled diet will regain all their weight, or more, in the next year. Achieving long term success means re-educating the way we eat and taking plenty of exercise. Recently in the British Medical Journal, a Danish research group showed that to keep weight off, it was better to stay on a low-fat diet (but not necessarily to restrict the amount of calories you eat) and to take some exercise. Even 10 minutes a day is better than nothing. Going out for a walk at lunchtime has to be better than eating a cream cake. It's a long-term investment.

It's easy for me to say what to do and I understand the frustration of trying to eat healthily. I also know that exercise can be boring. GPs hand out dietary advice and don't seem to achieve a great deal of success. In fact, we often hand the matter on to practice nurses to deal with. Maybe this is because of our own sense of frustration.